Process Biochemistry 50 (2015) 317–327 Contents lists available at ScienceDirect Process Biochemistry jo ur nal home p age: www.elsevier.com/locate/procbio Mechanism-based antidiabetic activity of Fructo- and isomalto-oligosaccharides: Validation by in vivo, in silico and in vitro interaction potential Sudhanshu Kumar Bharti a,∗∗ , Supriya Krishnan b , Amit Kumar c , Ashok Kumar Gupta a , Asish Kumar Ghosh a , Awanish Kumar d,∗ a Department of Biochemistry, Patna University, Patna, Bihar, India b Department of Personnel Management and Industrial Relations, Patna University, Patna, Bihar, India c School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, India d Department of Biotechnology, National Institute of Technology, Raipur, Chhattisgarh, India a r t i c l e i n f o Article history: Received 14 August 2014 Received in revised form 16 October 2014 Accepted 22 October 2014 Available online 31 October 2014 Keywords: Diabetes mellitus Fructo/isomaltooligosaccharides Docking PPAR- agonist a b s t r a c t This study evaluates the relative beneficial effects of 10% dietary intake of fructooligosaccharides (FOSs) and isomaltooligosaccharides (IMOs) and combination of FOS + IMO in poloxamer-407 (PX-407) induced type 2 diabetic Wistar rats. FOSs was produced from Aspergillus oryzae (MTCC5154) while IMOs and standards of 1-kestose, 1-nystose, 1-fructofuranosyl nystose and panose were procured. In silico dock- ing studies were performed by GLIDE program for each of the FOSs and IMOs for PPAR- activation and DPP-IV inhibition. Diabetic rats treated with FOS + IMO showed relatively more amelioration of glycemic and lipid dysmetabolism, remarkable reduction in oxidative markers, increased GLP-1 content as well as Bifidobacteria/Lactobacilli population in caecum than lone FOSs/IMOs treatment. Out of nine oligosac- charides docked from FOS and IMO; panose, nystose and kestose showed highest ranking binding mode with DPP-IV and PPAR- and were selected for in vitro study either alone or in combinations. On its own nystose showed potent DPP-IV inhibitory activity with an IC 50 of 146.8 M while panose at 20.2 M con- centrations showed 50% binding ability to PPAR--LBD. Combinations of oligosaccharides tested namely Nys + Pan, Nys + Kes and Pan + Kes demonstrated significant (p < 0.001) effect on PPAR-/DPP-IV bioassay. The results provide pharmacological evidence of FOSs and IMOs as antihyperglycemic mediated by their interaction with multiple targets operating in diabetes particularly nystose and pannose. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder that accounts for about 85–95% of all diagnosed cases of diabetes. It Abbreviations: FOS, fructooligosaccharide; IMO, isomaltooligosaccharide; PX- 407, poloxamer-407; T2DM, type 2 diabetes mellitus; OGTT, oral glucose tolerance test; SCFA, short-chain fatty acids; PPAR, peroxisome proliferator-activated recep- tor ; DPP-IV, dipeptidyl peptidase-IV; Nys, nystose; Pan, panose; Kes, kestose; CI, combination index; ROS, reactive oxygen species; AGEs, advanced glycation end products; GLP-I, glucagon like peptide-1; TZDs, thiazolidinediones; XP, extra preci- sion; PDA, potato dextrose agar; SPD, standard pellet dietp; NRC, National Research Council; PDB, protein data bank; LBD, ligand binding domain. ∗ Corresponding author. Tel.: +91 8871830586; fax: +91 7712254600. ∗∗ Corresponding author. Tel.: +91 9852883752. E-mail addresses: sudhanshu bharti@rediffmail.com (S.K. Bharti), awanik.bt@nitrr.ac.in, drawanishkr@gmail.com (A. Kumar). is characterized by abnormalities in glucose homeostasis in many organs, and is associated with considerable morbidity and mor- tality. Several treatment strategies are being used against T2DM, including the use of synthetic drugs [1,2]. Despite excellent thera- peutic potency, synthetic drugs can cause serious side effects, such as fluid retention, drug-induced hypoglycemia, liver malfunction, weight gain and cardiac dysfunction [3]. Extensive research has been carried out using rational drug design to identify and optimize new leads for molecular tar- gets of T2DM, which include nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-) [4,5], human incretin-degrading enzyme dipeptidyl peptidase IV (DPP-IV) [6,7]. PPAR- regulates glucose metabolism and fatty acid storage by enhancing insulin action [4–6]. DPP-IV is a membrane-bound, serine protease ectoenzyme responsible for the degradation and inactivation of a number of glucose-regulating incretin hormones like glucagon like peptide-1 (GLP-1). GLP-1 causes an increase in http://dx.doi.org/10.1016/j.procbio.2014.10.014 1359-5113/© 2014 Elsevier Ltd. All rights reserved.